1. Field of the Invention
The invention relates to electric vehicle charging stations that are external a vehicle. The vehicle is charged by connecting the charging station to a vehicle outlet. This invention more particularly relates to recharging stations and methods for their use that are adapted for incorporation into existing standard building electrical distribution systems by electricians as part of a building electrical distribution system retrofit or new construction. The recharging system structural features and operation of the present invention incorporate technology that is generally familiar to electricians, electric power and distribution services providers, and building electrical distribution system design engineers.
2. Description of the Prior Art
While there is considerable technology literature devoted to on-board electric vehicle charging systems, primarily from the vehicle manufacturers and technology designers, there is relatively less devoted to the practical solutions of how electric power will be routed from an electric power grid to the vehicle. As a practical matter, demand for electric vehicles will be limited by the public's perception that it will be able to find readily available recharging stations.
In order to start satisfaction of public perception that vehicle charging stations will be available to the public in the near future, the vehicle industry has driven a solution for at least one Society of Automotive Engineers type J1772 standardized electrical connector configuration that is adapted for connection to a standard vehicle outlet (analogous to a standardized appliance cord plug and wired device outlet). However, there is a substantial need to create electric vehicle recharging station infrastructure on an ad hoc, ongoing basis, as electric vehicles become a larger part of the entire vehicle transportation base.
Electric vehicle recharging places higher demands on an existing building electrical distribution system than, for example, replacing an existing kitchen refrigerator or electric clothing dryer. A closer historical example was when building electrical distribution systems had to be reconfigured to accommodate central air conditioning climate control systems. When central air conditioning system technology became prevalent, building electrical distribution system designers, power producer and distribution service providers and electricians had to configure system upgrades for both the retrofit and new construction market. The same types of challenges now face the industry as it conforms to demands for electric vehicle recharging applications.
Relatively high sustained current draws necessary to charge electric vehicle batteries requires building electrical distribution system upgrades to protect the building distribution system, the vehicle being charged, and their associated operators during charging operations. Additional building distribution system electrical hardware must be capable of meeting electric codes, and conform to design standards (e.g., Underwriters Laboratories, Canadian Standards Association, etc.) necessary for a building owner to obtain property insurance coverage. As a practical matter new recharging equipment technology incorporated into building electrical systems must be familiar to electrical system designers, governmental electrical inspection authorities, electricians, building maintenance specialists and recharging operators if it is expected to be adopted quickly and in an economically efficient manner.
Thus, a need exists in the art for an electric vehicle recharging station system and method that can be readily added as an additional branch to existing building electrical distribution designs by building electrical system retrofit or during new construction. In this manner, a consumer can choose to purchase an electrical vehicle with confidence that home or work electrical distribution systems can be upgraded to accommodate the vehicle charging station quickly by licensed electricians, and that the installation will be approved by inspection authorities during the subsequent building permit review process.